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HW2: Week 2 Problem Set Honors Chemistry Due Date: Friday, September 5th, 2014 Name: _____________________________________________ TP: ________ Directions: Complete each of the following problems on a separate sheet of paper. To be considered complete, you must have every answer completed on a separate sheet of paper, ALL WORK MUST BE SHOWN, and stapled directly to this handout. This problem set is due at the beginning of class on Friday, September 5th, 2014. Score: 1. Sketch two pieces of glassware: one that can measure volume to the thousandths place and one that can measure volume to the hundredths place. ___________ /20 2. How many significant figures are in each of the following? a. 12 e. 0.0000101 b. 1098 f. 1.01 x 10-5 c. 2001 g. 1000. d. 2.001 x 103 h. 22.04030 3. Perform the following mathematical operations, and express each result to the correct number of significant figures. a. 97.381 + 4.2502 + 0.99195 c. (0.102 x 0.0821 x 273) ÷ 1.01 b. 21.091 – 13.21 – 4.0215 d. (9.2 x 100.65) ÷ (8.321 + 4.026) 4. Perform each of the following conversions. Show all work! a. 8.43 cm to millimeters c. 294.5 nm to centimeters b. 2.412 cm to meters d. 1.445 x 104 m to kilometers 5. Ms. Joseph is planning on buying a new car. One model that she is considering gets 32 miles to a gallon of gasoline in highway travel. Another gets 14 kilometers to the liter. Which car has the better gas mileage? 6. A children’s pain relief elixir contains 80. mg of acetaminophen per 0.50 teaspoon. The dosage recommended for a child who weighs between 24 and 35 lbs. is 1.5 teaspoons. What is the range of acetaminophen dosages, expressed in mg acetaminophen/kg body weight for a children who weigh between 24 and 35 lbs.? 7. A material will float on the surface of a liquid if the material has a density less than that of the liquid. Given that the density of water is approximately 1.0 g/mL, will a block of material having a volume of 1.2 x 104 in3 and weighing 350 lb float or sink when placed in a reservoir of water? 8. A rectangular block has dimensions of 2.9 cm x 3.5 cm x10.0 cm. The mass of the block is 615.0 g. What are the volume and density of the block? 9. The density of pure silver is 10.5 g/cm3 at 20°C. If 5.25 g of pure silver pellets is added to a graduated cylinder containing 11.2 mL of water, to what volume level will the water in the cylinder rise? 10. Many times errors are expressed in terms of percentage. The percent error is the absolute value of the difference of the true value and the experimental value, divided by the true value, and multiplied by 100. Percent error = true value – experimental value x 100 true value Define Your Pride. Calculate the percent error for the following measurement: The density of an aluminum block determined in an experiment was 2.64 g/cm3. (True value is 2.70 g/cm3.) Define Your Pride.